Indoor tv antenna



May 13, 1958 M. B. PEREZ INDOOR TV ANTENNA 2 sheets-sheet 1 Filed July 29, l95 5 May 13, 1958 M. B. PEREZ 2,834,958

INDOOR TV ANTENNA Filed July 29. 1955 2 Sheets-Sheet 2 IN VEN TOR.

2,834,958 Patented May 13, 1958 INDUORTV ANTENNA Marcos B. Perez, Ciudad Trujillo, Dominican Republic Application July 29, 1955, Serial No. 525,334

6 Claims. (Cl. 343-751) This present invention relates to indoor TV antennas.

it is well known that there are a very great number of television receivers in use at the present time. Many of these receivers are situated in cities having apartment houses or other dwellings in which it is not convenient to erect outdoor antennas, even assuming that the high cost of outdoor TV antenna installations would not operate as an obstacle.

lt is an object of the invention to provide an indoor TV antenna which is capable of making possible excellent TV reception while being of low cost and while being very simple to install.

it is a further object of the invention to provide an indoor TV antenna which is adjustable in order to enable selection of a circuit best suited for the particular channel to which the TV receiver is tuned.

It is a further object of the invention to provide an indoor TV antenna which is of small size, which is of rugged construction, and which is comprised of a minimum number of operating parts.

One embodiment of the invention will be described by way of example in connection with the accompanying drawings, in which:

Figure 1 is a top elevational view of the exterior of the indoor TV unit showing a transmission line connected thereto;

Fig. 2 is a side elevational view of the antenna unit showing the relative disposition of the cooperating parts;

Fig. 3 is a section along the lines 3-3 of Fig. l, showing further constructional details;

Fig. 4 is a view of the interior of the antenna taken in the direction of the axis of the adjusting vmember and showing a portion thereof torn away, in order to make clear the arrangement of the parts for the two groups of channels; and

Fig. 5 is a fragmentary schematic view of the-electrical elements going to make up the circuit necessary` in Vorder to enable operation with a given channel.

While the antenna has particular utility for V. H. F., it is clear to those skilled in the art that U. operation can also be achieved by suitable proportiom'ng of the parts, physically and electrically. The antenna of Fig. 1 is indicated generally-by thereference numeral 10. A front plate 12 is provided, having thereon suitable indicia such as the numbers 2 through 13 covering 12 television channels. A U-shaped member 14 is provided having a front leg 16 and a rear leg i3 connected by a bridging member 20. A window 22 is provided in the front leg through which the various numbers identifying the channels can be discerned by the operator or viewer. Bridging member 20 is provided with an opening 2d extending therethrough. A suitable member such as a nail may be passed through opening 24 and secured to a wall for the purpose of supporting the antenna in operating position. It may be well to mention that the antenna should be arranged to be suspended in free space, without touching any object such as a wall in order to obtain the best results. i

If suspended in the manner described above, the transmission line 26 will always ldepend downwardly from antenna 10.

It will be seen that extending through front and rear legs 16 and 18, there is provided a shaft 30 integral with a knob 32 disposed at the front of the unit. Front plate 12 has an annular boss 34 connected by a suitable pin to shaft 30. A first disc 38 is provided having a centrally disposed boss keyed to shaft 30, disc 38 serving to carry the necessary electrical elements for six of the twelve channels. A second disc 40 is also provided having a centrally disposed annular boss also connected by a pin to shaft 30, disc 40 serving to carry the electrical elements necessary for the remaining six of the twelve channels. A disc of insulating material 42 is4 provided for suitably electrically separating discs 38 and 40.

Antenna lead in 26 is connected to a rotating, double pole type switch, one terminal 50 of which is visible in Fig. 3. A series of pin members 52 are provided which extend through the front of front plate 12, and which are arranged in an annular group co-axially about shaft 30, as is particularly evident from Fig. 1. As seen in Fig. 2, the lefthand ends of pin members 52 are adapted to engage the contacts 50 of the double pole switch carried by front leg 16.

it will be observed that upon rotation of knob 32 by the operator, the entire structure which is fastened to shaft 30 will rotate with the knob, whereas the U-shaped frame 16, 18, 20 will remain stationary` During the rotating process, the switch contacts 50 will contact pairs of'the pins 52, which are connected to circuits as will be described, each of which circuits is particularly adapted for use with the television channel, the number of which appears in the window 22.

It will be understood that any suitable detent means may be provided for insuring that when knob 32 is rotated, and when the desired channel appears in window 22, the appropriate contacts will be positively contacted by the switch contacts 50.

As will be evident from close inspection of Figs. 2, 3 and 4, two adjacent pin members will have their base ends made fast to, for instance disc 38. The pair of pin members 52011 either side of such first mentioned pair will have their base ends embedded in disc40. The circuit elements connected to one cooperating pair of pin members 52 will therefore be associated with, say, 'disc 38, while the circuitelements associated with the next -adjacent pair of pin members on either side of theV iir'st mentioned pair of pin members will lbe associated with disc member 40. The foregoing arrangement makes possible the arrangement of the terminals for both sections 38 and 40 on one side, allowing the use of but one single switch to cover all channels. Naturally if desired, and by use of more switches, the construction could bealtered so that the pin Vmembers having their base ends embedded in disc itl would not have to extend to the front of front plate 12.

While no casing has been described, it will be understood that the parts 12, 38, 42 and 40 may be enclosed circumferentially in any suitable way, as by a member having a knurled surface, making it easier to rotate the rotatable part with respect to the lixed part. Moreover, although the transmission line 26 is shown extending downwardly, there may be circumstances in which it might be desirable to arrange the antenna and its supporting means in such a way that the antenna wire will be directed upwardly therefrom.

Referring to Fig. 4, it will be seen that the various pairs of pin members 52 have associated therewith numbers identifying the channel. For Channel 2, pin A has associated thereto a resistor R1 in series with an inductor L1 and a capacitor C1, with the point of junction of the lead connection R1 and C1 being connected to A. Pin B has connected thereto one end of a resistor RZ, the other end of which is connected to one end of an inductor L2, the other end of which inductor is connected to one end of a capacitor C2, the other end of which capacitor is returned to pin B. As can be seen, the upper ends of capacitors C1 and C2 are interconnected by a resistor R3. Since cach cooperating pair of pins 52 will be of identical components in similar relation, there is no point in describing each of the twelve circuits involved. It is thought that the description of one circuit by Way of example will be entirely adequate for the purposes of those skilled in the art. Fig. 5 shows schematically the circuit just described.

Needless to say, the multi-station antenna being described increases the magnetic field, has a high pick-up sensitivity, which is induced to the selected channel eircuit, which, of course, is directly connected to the receiver. To obtain the eects desired, naturally the antenna is oriented with respect to the station selected. When the elements corresponding to the antenna for the channel being selected are in the top position with respect to the others and are directed to the desired station, the elements of the other antenna circuits in the group will operate as a reector. With the preset units described, the performl ance has been obtained the same as with broad band antennas which cover all of the twelve television channels, but without the low gain which is characteristic in the broad band antenna. The improvement is thought to result from the fact that each channel is separately selected and that therefore a good gain and sensitivity can be obtained for each channel.

Each of the resistors R1 and each of the resistors R2 for each of the antenna circuits may be 100 ohm, 1/2 watt carbon resistances. Each of the resistors R3 may be 56 ohm 1/2 watt carbon resistances. Each condenser C1 and each condenser C2 may be a .0l microfarad condenser. The inductors L1 and L2 may be coils made of number 30 magnetic wire, wound over a piece of insulated iron rod which is 5%2 inch in diameter and somewhere in the neighbotrhood of 1 inch in length, according to the following ta le: Y

Length in inches of #30 Magnet Wire for coil L1 or L2 Channel Needless to say, the iron rods over which the wire is wound should be very well insulated, since such rods function purely as magnetic cores. While one particular em-A bodiment of the invention has been described, it will be understood that variations can be made within the scope of the appended claims. For instance, one single such circuit could be provided for each channel which is very commonly used, though one single ixed antenna would y naturally not have the exibility of operation of the arrangement described.

What I claim as new and desire to protect by Letters Patent of the United States is:

l. An indoor TV antenna comprising a body member adapted to be located and oriented relative to a TV transmitter, a rst Contact and a second contact carried by said body member and adapted to be connected to the terminals of a TV receiver by a transmission line, and the following components carried by the body member: a first resistor, a tirst inductor, and a first capacitor connected in series, the junction of said rst resistor and rst condenser being connected to said lirst contact; a second resistor, a second inductor, and a second capacitor in series, the junction of said second resistor and said second capacitor being connected to said second contact, and a third resistor bridging the junction between said first capacitor and said rst inductor and the junction between said second capacitor and said second inductor, said inductors each including a coil of magnetic wire supported upon an insulated iron core.

2. An indoor TV antenna according to claim l, including a plurality of pairs of contacts, each cooperating pair of contacts having connected thereto a set of components as set forth.

3. An antenna according to claim 2, said antenna having a U-shaped supporting member, said body member being supported intermediate the legs of said U-shaped supporting member, a window in the front leg of said U-shaped supporting member, and indicia on the adjacent face of the body member corresponding to a TV channel to be selected.

4. An antenna according to claim 3, said body member being generally circular, a shaft extending centrally through said body member and rigid therewith, said shaft being journalled in the legs of said U-shaped supporting member and a control knob aixed to said shaft.

5. An antenna according to claim 4 in which the contacts are arranged in an annular circle about said shaft, said contacts having ends extending outwrdly from the front face of said body member, a switch member being provided and fixed to the front leg of said U-shaped supporting member, said switch member being adapted to contact the adjacent ends of the said contacts.

6. An antenna according to claim 5, said body member comprising a rst disc, half of said plurality of contacts having their lower ends embedded in said rst disc, a second disc spaced from said rst disc, and an insulating layer interposed intermediate said rst and second discs, the other half of said contacts having their lower ends embedded in said second disc, one-half of said components attached to the contacts carried by said rst disc, and the other half of said components attached to the contacts carried by said second disc.

No references cited. 

